A continuum of balance performance between children with developmental coordination disorder, spastic cerebral palsy, and typical development.

Background: Balance deficits are one of the most common impairments in developmental coordination disorder (DCD) and cerebral palsy (CP), with shared characteristics between both groups. However, balance deficits in DCD are very heterogeneous, but unlike in CP, they are poorly understood.

Aim: To unravel the heterogeneity of balance performance in children with DCD by comparing them with CP and typical development (TD).

Design: Cross-sectional case-control study.

Setting: Different outpatient settings and the community.

Population: Children aged 5-10.9 years with TD (N.=64, boys: 34, mean [SD] age: 8.1 [1.6]), DCD (N.=39, boys: 32, mean [SD] age: 8.1 [1.5], formal diagnosis [N.=27]), and CP (N.=24, boys: 14, mean [SD] age: 7.5 [1.4], GMFCS level I [N.=14]/II [N.=10], unilateral [N.=13]/bilateral [N.=11]).

Methods: We evaluated balance performance with the extended version of the Kids-Balance Evaluation Systems Test (Kids-BESTest). Between-group differences in domain and total scores (%) were assessed via ANCOVA (covariate: age), with Tukey post-hoc analyses (P≤0.01).

Results: Children with DCD and CP performed poorer than TD children on total and domain scores with large effects (domains: η²=0.25-0.66 [P<0.001], total: η²=0.71 [P<0.001]). Still, post hoc comparisons revealed that DCD children scored significantly better than CP on the total score and four domains (P≤0.009), while performing similarly on tasks related to stability limits (P=0.999) and gait stability (P=0.012).

Conclusions: There is a continuum of balance performance between children with TD, DCD and CP, but with great inter- and intra-individual heterogeneity in DCD and CP. DCD and CP children have difficulties with tasks requiring anticipatory postural adjustments, fast reactive responses, and with tasks that require complex sensory integration, suggesting an internal modeling deficit in both groups. This implies that these children must rely on slow conscious feedback-based control rather than fast feedforward control and fast automatic feedback. The performance of both DCD and CP children on their stability limits/verticality is similarly poor which further emphasizes a potential deficit in their sensory input and/or integration. Future research must focus on unraveling the control mechanisms, to further understand the heterogeneity of these balance deficits.

Clinical rehabilitation impact: The heterogeneous balance performances in both children with DCD and CP underscore the importance of comprehensively evaluating balance deficits in both groups. This comprehensive assessment contributes to a better understanding of individual balance deficits, thereby facilitating more tailored treatment programs.